The Younger Dryas wasn't just a climate shift. It marked a turning point in human and natural history that shows up in the archaeological record as abandonment. Sites occupied for centuries prior to this boundary suddenly go quiet. The Clovis culture, which had established itself across North America, appears to vanish from the record at this same horizon. Megafaunal extinctions sweep across the continent during this same narrow window. When you line up the geological evidence, the archaeological record, and the extinction data, they all point to the same moment in time. Something happened at the Younger Dryas boundary that fundamentally disrupted both human settlement patterns and the broader ecosystem. The question isn't whether there was a major event. The question is what kind of forcing mechanism could produce that constellation of effects simultaneously across such a wide geographic area.